Mold for concrete cisterns, &amp;c.



F. H. DUMBAULD, DEOD.

.T. A. BRUMBAUGH, ADMINISTRATOR.

MOLD FOR CONCRETE GISTERNS, 6w.

APPLICATION FILED MAR. 10, 1910. 1,088,218. Patented Feb. 24, 191

2 SHEETS-SHEET 1.

, llll'llll'llllllll ll INVENTOR UNITED STATES PATENT OFFICE. FREDERICK I-I. DUMBAULD, OF MCCUNE,Y\KANSAS; JACOB A. IBRUMBAUGI-I ADMINIS- TRATOR OF SAID DUMZBAULD, DECEASED.

MOLD FOR CONCRETE CISTERNS, 860.

To all whom it may concern Be it known that I, FREDERICK H. DUM- BAULD, of McCune, in the county of Crawford, and in the State of Kansas, have invented a certain new and useful Improvement in Molds for Concrete Cisterns, &c., and do hereby declare that the following is a full, clear, and exact description thereof.

The object of my invention is to enable the rapid and economical construction or erection of structures of concrete suitable for cisterns and other purposes, which in addition to the advantages of expeditious and economic construction, will be as strong as is necessary, and to this end my invention consists in the mold constructed substantially as hereinafter specified and claimed.

Referring to the accompanying drawings, Figure 1 is a perspective view of a mold embodying my invention, with parts assembled as they appear when used for molding a cistern with an arched or domed top; Fig. 2 a similar View of the same with portions of the apparatus and mold illustrated in Fig. 1 removed. Fig. 3 is a detail view in perspective of the oblique joint and lever, for the side wall mold sections; and Fig. 1 is a detail top plan view of a fragment of one of the side wall mold sections.

The mold that I have selected to illustrate my invention is one for the constructionof a cistern of circular form with an arched top or roof, and generally described, in such operation an excavation is made in the earth of a diameter as much larger than the mold as the thickness of the wall the cistern is to have, and in such excavation is placed the cylindrical portion 10 of the mold with its bottom edge resting on the bottom of the excavation, the concrete being poured into the annular space between the mold and the wall of the excavation, and thoroughly tamped or stamped. The cylindrical portion of the mold is gradually raised as the filling operation proceeds, so that it is possible to construct a cistern whose height is much greater than the height of the cylindrical portion of the mold. Having by means of the cylindrical portion of the mold formed the concrete wall to the height desired, a conical member 11 is applied to the top of the mold to which is applied the concrete that is to form the arched or domed top of the cistern, a hole of suitable'diameter of course being left in the top or arch at the center thereof,

Specification of Letters Patent.

Application filed March 10, 1910.

Patented Feb. 24, 1914.

Serial No. 548,413.

through which the mold, which is made in sections as hereinafter fully described, may be removed after the concrete has sufficiently hardened to support itself.

The cylindrical portion of the mold is made of a number of sections, and as I prefer to construct them, each consists of a framework 12 of wood to which is attached a covering of sheet iron, that projects a short distance at the top of the framework to form a vertical flange or rim 13. The wooden framework consists of vertical posts and curved horizontally extending bars arranged at suitable intervals apart vertically. Of course any number of sections may be employed to form' the cylindrical portion of the mold, but a convenlent number is six, and at the joints where ad acent sections abut they are secured together by a clip 14 that consists of an inverted U-shaped rod whose legs pass through holes in the framework of the sections. The legs diverge so that when forced into position they draw the sections together. At least one of the joints and if desired more of the joints, are miter joints, or oblique or inclined, to aid in assembling and separating the sections, and the clip or coupling at the miter joints is preferably provided with a handle 1410 to facilitate the horizontal movements of the sections in as sembling the sections or taking them apart by a pulling or pushing operation.

It is to be understood that I do not limit myself to any particular construction of mold sections, for if preferred, they may be made wholly of wood, iron or soft steel.

For raising the mold as the formation or construction of the concrete wall proceeds, any suitable raising or lifting device may be employed. For example, as shown in the drawings, an ordinary derrick 15 may be employed, with block and tackle 16, the hoisting rope 17 of which at its lower end is branched and attached by clevises 18 to a beam 19 that extends diametrically of the mold, and at each end has pivoted on the under side a block 190, which by being turned to a position in alinement with the beam projects beneath a block 20 that is secured to the under side of the top curved bar of the frame of one of the mold sections. By turning the block to a position at right angles from that stated, the beam may be released or freed from the mold.

To form the dome or arch of the cistern, the top of the mold is given the form of the frustum of a cone, it also, as before stated, being composed of sections or segments of any desired number, conveniently eight, for example, that at their lower broader ends rest on the upper edges of the cylinder 10, having a bearing against, and being supported laterally by, the vertical flange 13 thereat, and at their upper smaller ends resting against and supported by a ring 21. The ring 21 is supported by posts or uprights 22 that at their lower ends rest upon a diametrically extending beam 28 which at its ends rests upon and is supported by short vertical blocks 24 that rest upon the lower curved bars of the section frame 12, said .diametrically extending beam being held in position also by a bolt 25 that passes through the upper curved bar of the section frame and through the beam. It will be evident that after all the sections forming the conical top of the mold are in place, they mutually support each other by counterbalancing pressure on the ring 21, the outward thrust being sustained by the vertical flange 13 on the top of the cylindrical member 10 of the mold. The sections forming the conical top of the mold may be made of any desired material, and in any desired manner. As I prefer to construct them, each section is formed of a number of tapering bars 110 placed edge to edge that are nailed or tacked to several narrow strips of sheet iron, and then covered by a segmental shaped piece of sheet iron 111, that preferably projects at one side so as to overlap the contiguous edge of an adjoining segment, and thus assure the absence of any openings or spaces between adjacent sections. group of bars forming a segment or section is drawn tightly together by some suitable tension device, as for example, a turn buckle or a pair of twisted wires 26, as shown, attached to the outer bars of a group. To facilitate the removal of the arch forming sections, one of them at one of the outer corners is cut away to provide a small but sufficiently large opening 27 for the purpose. The arch supporting ring 21 is likewise made of sections or segments, it being conveniently made of three sections, two of the joints being on radial lines, and preferably the three parts being united at such points by hinges 28, the third joint 280 being preferably a miter or oblique joint to enable the collapsing or .folding together of the ring, and its opening to position for use and the formation of a proper joint when opened.

The manner of using my mold to forin a cistern has, I think, been sufliciently described already, and it will therefore not be necessary to further describe the manner of The using it. F or the removal of the mold from the completed cistern, after the concrete has become sufliciently hard to permit it, the ring 21 is collapsed by being turned inward upon its hinged oints to release the segments resting thereagainst and then the beams 19 and 23 are detached from the mold sides, and the sections forming the latter are then separated, all the parts referred to being thus placed in a condition for their removal through the hole at the top of the cistern.

Of course the mold may be of other forms than circular, as for example, a hexagonal or other polygonal form.

What I claim is- 1. A mold for concrete structures, comprising a sectional vertical member, a sectional dome shaped member, means to support the lower edge of the dome shaped member on the upper edge of the vertical member, a ring form support for the upper end of the dome shaped member, the upper end of the sections forming said dome shaped member bearing against the outer side of said support, but being unattached thereto, and means connected with the vertical member on which said ring-form support rests.

2. A mold for concrete structures, comprising a vertically movable hollow member whose exterior forms the molding surface, said member being formed of separable sections, each section being composed of a frame work and a sheet metal covering that projects above the frame work forming a flange, a cross beam detachably connected with said member, lifting means connected with said cross beam, a dome forming member composed of sections whose lower edges rest upon the top edge of said hollow member and bear against the flange at the top of said hollow member, an open support against which the upper edges of said dome member forming sections rest, and means detaehably connecting said open support and said hollow member.

3. A mold for structures of concrete and the like, comprising a vertical member, a dome forming member composed of sections, the lower ends of the sections resting on the upper edge of the vertical member, an open support against whose outer side the upper ends of said sections bear, a cross beam detachably connected with said vertical member and supported thereby, and means for supporting said support from said beam.

In testimonv that I claim the foregoing I have hereunto set my hand.

FREDERICK II. DUMBAULD.

' lVitnesses:

O. G. MoN'rooMnnY, J. T. Cross.

copies of this patent may be obtained for five cents each, by Washington, D. O.

addressing the "Commissioner of Patent, 

